>>96406104
From what I understand this distinction mainly follows from the curse status. The cursed ones now known as "dark" while uncursed are "light". But it was not like that before the curse.
>>96406092
They could have a separate empire of just elves. And they could got their dark prefix after curse. But it's just speculation really. We do not have a single mention of dark elves before the curse. The only know of Maevian kingdom that could be founded by any elves.